Fan wheel



Dec. 15, 1953 D. F. WUERFEL 2,662,686

FAN WHEEL Filed April 18, 1952 2 Sheets-Sheet l INVENTOR.

a g/vnw A ll/l/ERFEL A TTOP/VEY Dec. 15, 1953 D. F. WUERFEL FAN WHEEL 2Sheets-Sheet 2 Filed April 18, 1952 INVENTOR. DOA/0L0 F. LUUERE L BY M&

A 77' OE/VE Y Patented Dec. 15, 1953 UNITED STATES PATENT OFFICE FANWHEEL Donald F. Wuerfel, Detroit, Mich., assignor to Edmund E. Hans,Detroit, Mich.

2 Claims.

This invention relates to improvements in fan wheels or impellers, andrefers particularly to a fan wheel or impeller including a disc havingblades extending at right angles from its periphery and parallel withits axis.

It is an object of the invention to provide a fan wheel or impeller ofthe type above stated wherein the blades are all integral with a singledisc, and their number and width are such as to provide maximumefficiency and air output, thereby rendering it unnecessary to utilize aplurality of superimposed concentric blade-equipped discs in order toobtain efiicient operation; and wherein the disc and all its blades areblanked and formed in two simple operations.

Another object of the invention is to provide such a fan wheel orimpeller wherein the disc and blades are so reinforced and strengthenedby their formation and relative arrangement that no appreciabledistortion or deformation occurs when the fan is rotated at relativehigh speed and the blades are of normal length. Moreover I also providesupplemental means which may be employed for reinforcing the blades andpreventing them from spreading when they are unusually long or the fanis intended to be rotated at very high speed.

A further object of the invention is to provide such a fan wheel orimpeller wherein the inner face of the disc is of irregular form so thatno air flowing into the fan for discharge by the blades can remainstationary adjacent the said inner face but is retained in motion forimmediate discharge. It will also be noted that the blades are so formedrelative to the disc that they are effective throughout their entirelength from the said disc to their outer extremities for dischargingair.

Figure 1 is a plan view showing the blank out of which the fan wheel ismade, and

Figure 2 is a side view thereof, partly in section.

Figure 3 is a perspective view of the fan wheel, and

Figure 4 is a side elevation thereof.

Figure 5 is a plan view looking into the fan wheel, and onto the innerface of the disc.

Figure 6 is an inverted plan view looking onto the outer face of thedisc.

Figure 7 is an enlarged section on the line 1--l of Figure 5, and alsoincludes an annular reinforcing member to prevent the blades fromspreading at very high speeds.

Figure 8 is an enlarged sectional view on line 88 of Figure 6.

Referring to the drawings, l designates a blank 2 stamped out of asingle sheet of material, usually aluminum. This blank consists of anannular disc 2 centrally apertured at 2a and having a plurality ofidentical, uniformly spaced fingers 3 extending outwardly therefrom.These fingers, which are of uniform width throughout their length,consist of inner portions 3a which are radial to the axis of the disc 2;intermediate portions 31) which are curved; and outer portions which aredisposed at substantially degrees to imaginary lines extending radiallyfrom the axis of the disc and passing centrally through the innerportions 3a. The opposite corners of the fingers 3 are usually roundedat their outer extremities as shown at 30!, and the adjacent innermargins of each adjacent pair of fingers 3 are connected bysubstantially semi-circular peripheral portions 2b of the disc 2 so thatthe inner ends of the fingers 3 are slightly spaced from one another,and also to strengthen the fingers at their roots.

When the blank I is formed the fingers 3 are folded to constitute blades4 having their outer portions 4a extending longitudinally substantiallyparallel with the axis of the disc 2 and transversely substantiallyradial to the said axis. During this folding operation the blades 4 arealso bent transversely throughout their length to add strength andrigidity, the formation of their outer portions 411 being such thattheir leading faces 41) are transversely somewhat concave to increasetheir operating efficiency, and this concavity at the inner extremities,as illustrated in Figure 8, provides means for strengthening thejunctures between the blades and the disc. When the blades 4 are formedtheir inner extremities 40 remain substantially radial to the disc axisand their intermediate elbow portions ad, which are formed out of thecurved intermediate portions 3b of the fingers, are so folded that theinner and outer edge faces of the outer portions 4a of the blades liesubstantially in radial alignment relative to the axis of the disc 2.Moreover the folding is such that the outer ends of the inner bladeportions 40 and the adjacent extremities of the elbow portions 4d notonly provide very strong rigid connections to support the outer portionsto but also constitute emcient operating parts of the blades so that airis discharged by the blades throughout their entire length forimmediately adjacent the disc 2 to their outer extremities.

Prior to completion of the forming operation the inner annular portions20 of the disc 2 is dished or laterally offset in the same direction asthat in which the blades 4 extend; and formed in the disc 2 andextending the entire distance from the annular dished portion 20 to theinner extremity 4c of each blade is a rib or corrugation 2d whichprojects laterally from the outer face of the disc 2, is radial to thedisc axis, and is in radial alignment with the said inner extremity ofone of the blades. It will thus be noted that these ribs 2d project fromthe opposite face of the disc to the dished annular portion 20. On theinner face of the disc 2 radial grooves or flutes 2e are formed whichconstitute the inner sides of the said ribs or corrugations 2d andbecause of the circularly irregular surface thus formed, air enteringthe fan wheel for dis charge thereby cannot lie dormant against theinner face of the disc.

The ribs 2d materially strengthen the disc and this strengthening ispartly attributable to the fact that the ribs project on one side of thedisc and the dished portion 20 projects on the other side. Again due tothe fact that the ribs 2d are in radial alignment with, and form inwardconcave continuations of the concave inner extremities of the blades,further stiffening both of the disc 2 and the blades 4' results. Thoughthe blades are transversely somewhat folded throughout their lengththeir surface width is uniform throughout their length, and again byshaping the. blank as shown and described herein the required number ofblades of the proper width to. affordmaximum efficiency are all formedintegral with a single disc.

The central aperture 2a of the disc 2 is usually enlarged after theforming operation has been completed to insure absolute concentricity ofthe disc 2-, and it, is: then mounted upon a tubular hub 5. In thepresent instance the hub 5 is of reduced diameter from one end as shownat 5:2. This reduced hub portion is inserted through the aperture 2a,preferably with a washer E. lying againstv each side of the disc, andthe outer extremity of. the reduced hub end is then riveted over asshownat Bbto; hold the. disc'2 and washers 6 immovable on the hubfor rotationtherewith.

Due. to the reinforcement of the disc 2 and blades 4" above, describedit is found that my fan Wheels. are so rigid that they will not show anyperceptible distortion when made, of relatively thin. metal provided theblades. are of normal length-and the fan wheel is rotated at normalspeeds. If fans having exceptionally long. blades are to be rotated atvery high speeds an annular reinforcing member may be utilized toprevent the blades: from, spreading. Figure '7 shows an annularreinforcing member consisting of a wire ring 1. engaging grooves 8'formed", in the pres.- ent instance, in: the outer peripheries of theblades 4 adjacent their outer ends.

While in the foregoing: the preferred embodiment. of the invention habeen described and shown iti'ss understood. that. alterations: andmodifications may be'made thereto. provided the said alterations andmodifications fall within the scope of theappended claims.

What I claim is:

l. A fan wheel comprising an annular sheet metal disc having its innerannular portion dished or laterally offset relative to the outerperipheral portion of the disc, blades integral with and projecting fromthe disc, ribs or corrugations in the disc and projecting laterallyoutward from the side of the disc remote from its offset annularportion, said side constituting the outer face of the disc, each ribbeing substantially in radial alignment with one blade, each blade beingfolded from adjacent its inner extremity so that the outer portion ofthe blade extends longitudinally substantially parallel with the axis ofthe disc and transversely substantially radially to the disc axis, andsaid blades having said outer portions transversely curved whereby theirleading faces are somewhat concave, each rib extending into an adjacentblade and terminating at the outer end of the blade between the sideedges of the blade toform said transverse curvature, and the inner faceof'said" disc having radial grooves therein extending outwardly fromsaid laterally offset portion to said blades whereby air cannot liedormant against the inner face thereof.

2. A fan wheel comprising an annular sheet metal disc having its innerannular portion dished or laterally offset relative to the outerperipheral portion of said disc, blades of uniform surface widththroughout their length integral with and projecting from said disc, theinner extremities of the blades being radial to the disc axis, ribs orcorrugations formed in said disc and projecting from the side thereofremote from the offset annular portion, said side constituting the outerface of the disc, each rib being in substantial radial alignment withboth the inner extremity and the outer portion of one. blade andextending from said offset annular portion into and forming an integralpart of the inner end 01" that blade, each blade being folded adjacentits inner extremity so that its outer portion extends longitudinallysubstantially parallel with the axis of the disc and transverselysubstantially radially to said axis, and the inner face of said dischaving radial grooves therein extending outwardly from said laterallyoffset portion to said blades whereby air cannot lie dormant against theinner face'thereof.

